1. Field of the Invention
This invention relates to a method of producing a laminated molding united with an facing material on its surface.
2. Description of the Related Art
Conventionally, a laminated molding united with a flexible facing material on its surface has been known and used for a car interior ornament such as a sun-visor and a headrest or an air current control valve used in an air conditioner for a vehicle. According to the aforementioned laminated molding, its surface is covered with the facing materials having flexibility, therefore, a nice feel can be afforded when, for example, a hand touches with the surface and further decorativeness can be afforded when fabric is used as the facing material.
Since an increase in the thickness of the facing material enables the facing material to have fine cushioning properties, if the laminated molding is used for a cover of a console-box and so on, noise generating when closing it, vibration in driving and so on can thus be controlled.
Furthermore, since the facing material having the cushioning properties is capable of sealing a gap, using the laminated molding for the air current control valve of the air conditioner for the vehicle, fine sound insulation, sealing state and so on can be afforded to the air current control valve.
Following method can be used for producing the laminated molding.
A. A method of producing to adhere the facing materials with adhesives and so on to the surface of the molding produced by an injection mold, previously.
B. A method of producing by a compress mold which compresses a melting synthetic resin fed into a cavity in a state of clamping between the two facing materials adhered with an impregnated prevention sheet (Japanese Patent Application Publication No. 2-25806).
C. A method of producing with the injection mold which the melting synthetic resin controlled relatively at low degree of an injection pressure is fed between the two facing materials after the mold preparing the two facing materials therein is completely closed, and at the same time, the fed melting synthetic resin is cooled and solidified in a low temperature under a retained pressure, relatively (Japanese Patent Application Publication No. 3-60297).
D. A method of producing with an injection compress mold which the melting synthetic resin is fed between the two facing materials before the mold preparing the two facing materials are clamped, and the mold fed completely with the melting synthetic resin is clamped (Japanese Patent Application Publication No. 5-83056).
The aforementioned producing methods A-D have respectively the following disadvantages a-d.
a. Disadvantages are that productivity becomes low by reason of an adhering process taking a long time, because each molding should be adhered with the facing materials one by one, and considering a disadvantage as for degeneration of a work environment, sufficient adhesive strength cannot be obtained by adhering with adhesives.
b. Disadvantages are that cycle time of molding processes for each molding becomes longer, because an extruder nozzle of feeding with the melting synthetic resin into the mold is required to move to and form the inside of the mold, whenever the melting synthetic resin is fed, and since the facing materials should be adhered with an impregnated prevention sheet, this results in an increased production time.
c. Disadvantages are that since the injection pressure is controlled at relatively low degree, it takes a long time to feed with the synthetic resin, whereby cycle time of molding processes becomes longer.
On the other hand, if the injection pressure is controlled at high pressure, the cycle time of the molding process can be shorter. Other disadvantages, whereby the quality of the facing materials become inferior, are produced by the following difficulties.
1 The facing materials are pushed in a horizontal direction, so that the surface of the facing materials wrinkle. PA1 2 When the grained facing materials are used, an uneven pattern grained on the facing materials, result in the disorderly grained pattern. PA1 3 When a fabric sheet is used as the facing materials, filaments on the fabric sheet are lain down, resulting in a rougher surface. PA1 4 When the thick facing materials are used, the facing materials are crushed so that their fine cushion property is lost. PA1 1 Each facing material is affixed to the inside of the mold-face opposite one another in the mold of the opening state. PA1 2 When the mold closes, a movable half-member of the mold stops moving before it reaches a completely closed state with a predetermined interval to secure the compression margin in order not to be reversed and not to be opened any more. PA1 3 The melting synthetic resin is fed into the mold by driving an injection device. PA1 4 Just before or after the finishing feed, a compression process to add the compressive force to the inside of the mold starts to cause the melting synthetic resin in the mold to be filled with spreadability by the compressive force. PA1 5 Just after the resin is filled throughout the mold, the compressive force adding to the mold is decreased. PA1 6 After a surface temperature of the resin is decreased, before the melting synthetic resin is solidified, the compressive force adding the mold is increased again to cause the resin in the mold to maintain its predetermined configuration. PA1 7 After the resin is cooled and solidified, the mold is opened to take out the molding. PA1 8 After finishing the injection, a preparative plasticization is started for the next injection molding. PA1 9 While the mold is almost closed and the facing material is compressed to an extent that the melting synthetic resin is not deformed or not to be spread by compression, the melting synthetic resin starts feeding into the mold. After the melting synthetic resin is filled to an extent that the melting synthetic resin covers at least the hole opened on the outer-face to correspond with the gate, a predetermined compression margin is secured by opening the mold while the feed of the melting synthetic resin is continued as it is, and then the feed of the melting synthetic resin is finished.
d. Disadvantages are that quality of the facing materials become inferior, producing the same difficulty as the aforementioned 1 to 4, because the melting synthetic resin is molded by clamping the mold, so that the large compressive force is required to be continually added to the melting synthetic resin and the facing materials in the mold until a molding process completes, with the result that the facing materials are strongly pressed with the high compressive force.
It is an object of the present invention to provide the method of producing the laminated molding, in which the molding time in a cycle of the process is shorter and further quality of the facing materials is not inferior.